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(No Model.)

G. R. WILLIAMS.

THERMOSTAT.

Patented Feb. 10, 1885.

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"NITED STATEs PATENT OFFICE;

GEORGE R. WILLIAMs, OE ITHACA, NEW YORK.'

THERMOSTAT.

SPECIFICATION forming part of Letters Patent No. 511,933, dated February 10, 1885. i Application filed February 21,1894. (No model.) V

aca, inthe county of Tompkins and State of New York, have invented an Improvement in Thermostats, of which the following is a description.

In order that myinvention may be fully unv-4 derstood, 4I will proceed to describe :it with reference to the accompanying drawings, in which Figure l is a front view of the thermalbar support. Fig. 2 is an end View of my machine (for governing the electric current) connected to afurnace-door. Fig. 3 is a side ele- Fig. Liis a horizontal section of the thermal-bar support on the line 4 4, Fig. l.

The thermal bar A consists of a strip of hard rubber, a, 4fastened to a strip of metal,

a', making together a flat bar which will tu-rn I'roin'a straight line in one or other direction as affected byheat or cold, on account of different rates of expansion in thesel two` mate'- rials. This form of 'thermal bar I do not claim as new. The bar is secured to, a post or arm, c', at one end, to which is attached a battery-wire, l. The other end of the bar vis free and extends between two adjustable contact-points, B C, mounted on a slide, D,adapt ed to be moved to the right or left transversely of the bar by means of an adjustable indicator-slide, E, having adiagonal slot, e, through which a pin, d, on the slide D is inserted, the

4indicator-slide being confined to a straight path by means of grooved plates or guides F, and moved vertically by a screw, G, so that any desired adjustment can be readily accomplished. The contactpoints slide has an arm, d', through which and the contact-point B a screw, b, is passed to adjust the point and permit the narrowing or Widening of the limit of variation between the points and bar. For convenience, an ordinary thermometer, H, is placed parallel with lthe thermal bar, the indcator-slide Ebeing provided with a pointer, I, at the top to indicate on the thermometer the heatlimit at which contact of the bar with a point will be made.

In Figs. 2 and 3 I show my machine for operating thedamper or-ventilator. In Fig. -2 5o I show the machine connected to thedoor of a stove or furnace. n

J is the usual door for feeding the stove lor furnace. K is a damper having journals Ick', i

by which it has bearings in lugsj,so as to re-V .l l y volve on the door.

' L is the shaft of the machine, mounted on suitable standards Z, and connected to the journal k" of the damper ,by means of a universal joint, M, in line with the door-hinge, so that mechanism for regulating the damper shall not in the least interfere with the free use of the door.

N is a drum'on the shaft, having a oord, n, and weight n', which give power to the shaft 65 to keep the damper-in place against any counter-draft, or to move it promptly, when de- Sred.

O isa ratchet-,wheel on the shaft L, having four equidistant teeth, o.

l? is an electro-magnet so placed in relation to this wheel that the vibrating arm Q3, upon which its armature q is placed, shall act as a pawl to engage the teeth, and shall be held tirmlyagainst the wheel-by a spring, q', except 7 5 when drawn away by the magnet. Upon the face of the wheel are segments of metal R R', opposite each other, and' each extending alittle more than a quarter-circle and equidistant from the center of the wheel.

's ot'- the wire 2 from the heat side or contactpoint B and one of the segments R, the other end of this segment being in contact with another slight spring, T, secured to bindingpost t of magnet-wire 3. The magnet is connected to the battery by wire 4. The electric current is ready to iiow through the contactpoint so soon as themovement of the free end of the bar makes contact with either point; When an electric current passes through the magnet, the pawl Q is drawn away, and wheel O, with the axle L, revolves, turning the damper until the current stops, when pawl Q,

The spaces r of 8o vthe circle between these segments are filled at once comes to position against the Wheel, stopping the revolution at the iirsttoo'th. So soon as the thermometer shows the desired limit of heat the contact is made as before described. The current at once gives power to the magnet to draw pawl Q out of the tooth, where it has rested, and the wheel, shaft, and damper begin to turn; but early in the movement the spring S leaves and passes beyond .another quarter-turn closing the damper to start'anew the warming process.

Having thus described my invention, the following is What I claim as new therein and desire to secure by Letters Patent:

1. In a thermostat, the combination, with a thermal bar, of a slide carrying contact-points on opposite sides'of the bar,.and devices for' adjusting the slide and the points thereon transverselyof the bar, asset forth.

2. In a thermostat, the combination, with a thermal bar, of aslide carrying contact-points, Aan indicator-slide by which the contact-points slide is adjusted transversely of the bar, a pointerto the indicator-slide, and a thermom- A.eter by which the adjustment regulated, as set forth. v

of the slides is 3. In a thermostat, the combination, with a thermal bar, of the slide D, having contactpoints B and C, an arm', d', and adjustable screw b, passed through the arm and contactpoint next to the arm, as set forth.

4. In a thermostat, the combination, with a thermal bar,'.of the slide D, having contactpoints B and C, and a pin, d,the indicatorslide E, having a diagonal slot, c, to receive the pin on the contact-points slide, and a pointer, I, and a thermometer in connection with the pointer, as set forth.

5. In a thermostat, the combination, Witha thermal bar, contact-points, a shaft, and means to rotate the shaft, of a toothed wheel O, metal segments R R on the face of the wheel, elecf tro-magnet l?, vibrating arm Q., to engage the teeth, slight springs S, I,'and U,'to bear on' the segments and connect the magnet vth rough the arm' with the contact-points until vone of the springs leaves a segment, as set forth.

6. In a thermostat, the combination of a thermal bar, contact-points, shaft, means to rotate the shaft, a paw-l to retain shaft from movement, an electro-magnet to release the" paWl from the shaft, a hinged door, a damper' journaled to the hinged door, anda universal joint connecting the shaft with the damper,

the joint permitting the door to be opened and j closed' at will, as set forth.

GEO. R. WILLIAMS.

Witnesses:

R. B. WILLIAMS, F. H. RoMER. 

